CVE-2021-29455

Missing validation of JWT signature in `grassrootza/grassroot-platform`

MEDIUM
5.3
CVSS Score
Published: April 19, 2021 at 07:05 PM UTC
Updated: June 17, 2026 at 03:47 AM UTC
2 products affected across 2 vendorsGrassroot PlatformGrassroot Platform

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.8%

Description

Grassroot Platform is an application to make it faster, cheaper and easier to persistently organize and mobilize people in low-income communities. Grassroot Platform before master deployment as of 2021-04-16 did not properly verify the signature of JSON Web Tokens when refreshing an existing JWT. This allows to forge a valid JWT. The problem has been patched in version 1.3.1 by deprecating the JWT refresh function, which was an overdue deprecation regardless (the "refresh" flow is no longer used).

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.3.1
Affected range stops below 1.3.1, so it looks safe — our inference, not a vendor statement
v < 1.3.1
Affected range stops below 1.3.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-347

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